JP2000218113A - Laminated nonwoven fabric for filter and filtration method using the same - Google Patents
Laminated nonwoven fabric for filter and filtration method using the sameInfo
- Publication number
- JP2000218113A JP2000218113A JP2163699A JP2163699A JP2000218113A JP 2000218113 A JP2000218113 A JP 2000218113A JP 2163699 A JP2163699 A JP 2163699A JP 2163699 A JP2163699 A JP 2163699A JP 2000218113 A JP2000218113 A JP 2000218113A
- Authority
- JP
- Japan
- Prior art keywords
- nonwoven fabric
- laminated
- filtration
- filter
- filling rate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000004745 nonwoven fabric Substances 0.000 title claims abstract description 129
- 238000001914 filtration Methods 0.000 title claims abstract description 65
- 239000000835 fiber Substances 0.000 claims abstract description 36
- 239000011148 porous material Substances 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 9
- 239000007788 liquid Substances 0.000 claims description 10
- 239000000155 melt Substances 0.000 claims description 4
- 238000012856 packing Methods 0.000 abstract description 6
- 238000011144 upstream manufacturing Methods 0.000 abstract description 6
- 239000010410 layer Substances 0.000 description 20
- -1 polyethylene Polymers 0.000 description 17
- 239000004743 Polypropylene Substances 0.000 description 13
- 239000002245 particle Substances 0.000 description 13
- 229920001155 polypropylene Polymers 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 8
- 239000004744 fabric Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 239000004750 melt-blown nonwoven Substances 0.000 description 7
- 238000003490 calendering Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 229920001410 Microfiber Polymers 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- 229920000098 polyolefin Polymers 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000004927 fusion Effects 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- OWEGMIWEEQEYGQ-UHFFFAOYSA-N 100676-05-9 Natural products OC1C(O)C(O)C(CO)OC1OCC1C(O)C(O)C(O)C(OC2C(OC(O)C(O)C2O)CO)O1 OWEGMIWEEQEYGQ-UHFFFAOYSA-N 0.000 description 1
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 1
- GUBGYTABKSRVRQ-PICCSMPSSA-N Maltose Natural products O[C@@H]1[C@@H](O)[C@H](O)[C@@H](CO)O[C@@H]1O[C@@H]1[C@@H](CO)OC(O)[C@H](O)[C@H]1O GUBGYTABKSRVRQ-PICCSMPSSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920001707 polybutylene terephthalate Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920002215 polytrimethylene terephthalate Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 239000012209 synthetic fiber Substances 0.000 description 1
- 239000012085 test solution Substances 0.000 description 1
- 238000003856 thermoforming Methods 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Filtering Materials (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はフィルター用途に好
適な不織布積層体に関する。TECHNICAL FIELD The present invention relates to a nonwoven fabric laminate suitable for filter applications.
【０００２】[0002]
【従来の技術】従来より合成繊維などの極細繊維よりな
る不織布は、小さいポアーサイズを有する特性から気液
フィルターとして利用されてきた。2. Description of the Related Art Conventionally, nonwoven fabrics made of ultrafine fibers such as synthetic fibers have been used as gas-liquid filters because of their small pore size.
【０００３】昨今のフィルター精度の向上の要求に応え
るため、メルトブロー法や分割繊維で得られる極細繊維
を用いられている。さらに濾過精度を向上させるために
カレンダー加工などにより充填率を高くしてポアサイズ
を小さくして濾過精度をあげるなどの工夫もされてい
る。しかしながら、不織布の充填率を高くしても孔径の
バラツキが大きく濾過精度が上げにくいという問題があ
った。濾過精度を上げるために充填率を高くすると不織
布の地合のバラツキにより、局所的に繊維の存在率が高
い部分で繊維が潰れてフィルム化して濾材として有効に
利用されない部分がでるという問題があった。また、濾
過精度を上げるために濾材を積層して用いることも実施
されるが、濾過操作時に濾過圧により不織布の各層が崩
れてしまうという問題点があった。このような問題の解
決手段として特公平5-41284号公報には、不織布を積層
状体で加熱一体化する手段が提示されている。これによ
り単層不織布を用いた場合、孔径がより均一になり、ま
た型くずれをおこしにくくなるが、濾過ライフ及び濾過
精度はともに不充分であった。[0003] In order to meet the recent demand for improvement in filter accuracy, ultrafine fibers obtained by a melt-blowing method or split fibers have been used. In order to further improve the filtration accuracy, various measures have been taken, such as increasing the filling rate by calendering or the like and reducing the pore size to increase the filtration accuracy. However, there is a problem that even if the filling rate of the nonwoven fabric is increased, the variation in the pore diameter is large, and it is difficult to increase the filtration accuracy. If the filling rate is increased to increase the filtration accuracy, there is a problem in that the fibers are locally crushed in a portion where the fiber abundance is high and formed into a film due to a variation in the formation of the nonwoven fabric, and a portion which is not effectively used as a filter medium appears. Was. Further, in order to increase the filtration accuracy, a filter material is laminated and used, but there is a problem that each layer of the nonwoven fabric is broken by a filtration pressure during a filtration operation. As means for solving such a problem, Japanese Patent Publication No. 5-41284 discloses a means for heating and integrating a nonwoven fabric in a laminated body. Thus, when a single-layer nonwoven fabric is used, the pore diameter becomes more uniform and the shape is less likely to be lost, but both the filtration life and the filtration accuracy are insufficient.
【０００４】[0004]
【発明が解決しようとする課題】本発明は、フィルター
濾過精度と濾過ライフとのバランスに優れた高精度濾過
フィルターの提供を可能にすることを課題とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-precision filtration filter having an excellent balance between filtration accuracy and life.
【０００５】[0005]
【課題を解決するための手段】本発明は、上記課題を解
決すべく鋭意研究を重ねた結果達成されたものであり、
フィルターとして特に好適な下記の不織布構造をとる。Means for Solving the Problems The present invention has been achieved as a result of intensive studies to solve the above problems.
The following nonwoven fabric structure particularly suitable as a filter is adopted.
【０００６】即ち、第１の発明は、繊維径が0.1〜6μ
ｍ、目付が15〜100ｇ／ｍ2である不織布が少なくとも２
層以上積層されており、上層（上流）側の不織布の充填
率が0.3〜0.8であり、下層（下流）側の不織布の充填率
が0.01〜0.25であることを特徴とするフィルター用積層
不織布である。また第２の発明は、第１の発明において
上層側と下層側の不織布の充填率の比上流側の方が大き
く、その比が3〜10であることを特徴とするフィルター
用積層不織布である。更に第３の発明は、前記第１ある
いは２の発明において上層側の不織布の平均孔径が0.2
〜5.0μｍであり、下層側の不織布の平均孔径が0.5〜30
μｍであることを特徴とするフィルター用積層不織布で
ある。第４の発明は、積層される不織布の少なくとも１
層がフィブリル状繊維を５〜３０重量％含有する前記第
1〜３の発明に記載のフィルター用積層不織布である。
また、第５の発明は、２ないし５層隣接して積層される
各不織布が目付の変動率が１０％以下であるメルトブロ
ー法により得られた不織布であって、隣接する不織布の
上層側の不織布の充填率が0.4〜0.6であり、下層側の不
織布の充填率が0.01〜0.25である積層部を少なくとも１
カ所以上有することを特徴とする前記第１〜４の発明に
記載のフィルター用積層不織布である。更に、第６の発
明は、前記第１〜６の発明の何れかに記載の積層不織布
をフィルターに用いて、粘度が2〜1000ｃｐ（センチポ
イズ）の液体を濾過速度0.1〜50ｃｍ／分の濾過速度で
濾過する方法である。That is, in the first invention, the fiber diameter is 0.1 to 6 μm.
m, nonwoven basis weight is 15 to 100 / m 2 is at least 2
A laminated nonwoven fabric for a filter, wherein the nonwoven fabric of the upper layer (upstream) has a filling rate of 0.3 to 0.8 and the nonwoven fabric of the lower layer (downstream) has a filling rate of 0.01 to 0.25. is there. Further, a second invention is a laminated nonwoven fabric for a filter, wherein the ratio of the filling ratio of the nonwoven fabric on the upper layer side and the lower layer side in the first invention is larger on the upstream side, and the ratio is 3 to 10. . Further, in the third invention, the average pore diameter of the nonwoven fabric on the upper layer side in the first or second invention is 0.2.
~ 5.0μm, the average pore size of the lower nonwoven fabric is 0.5 ~ 30
It is a laminated nonwoven fabric for filters characterized by having a thickness of μm. The fourth invention provides at least one of the laminated nonwoven fabrics.
The above-mentioned layer, wherein the layer contains 5 to 30% by weight of fibril-like fibers
It is a laminated nonwoven fabric for filters according to the inventions of 1 to 3.
A fifth invention is a nonwoven fabric obtained by a melt blow method in which each of the nonwoven fabrics laminated two to five layers adjacent to each other has a basis weight variation of 10% or less, and the nonwoven fabric on the upper layer side of the adjacent nonwoven fabrics Is 0.4 to 0.6, and at least one laminated portion having a lower layer nonwoven fabric filling rate of 0.01 to 0.25 is used.
The laminated nonwoven fabric for a filter according to any one of the first to fourth inventions, wherein the nonwoven fabric has a plurality of positions. Further, a sixth invention uses a laminated nonwoven fabric according to any one of the first to sixth inventions as a filter, and filters a liquid having a viscosity of 2 to 1000 cp (centipoise) at a filtration rate of 0.1 to 50 cm / min. It is a method of filtering with.
【０００７】[0007]
【発明の実施の形態】本発明の積層不織布に用いられる
不織布は、繊維径が0.1〜6μｍ、目付が15〜100ｇ／ｍ2
の不織布であることが必要である。繊維径が0.1μｍよ
り細いと不織布を加熱して充填率を高くしても不織布の
剛性が低く、濾過圧によって型くずれが起こりやすくな
るとともに濾過ライフが短くなってしまう。繊維径が６
μｍより大きいと、濾過ライフを改善することができな
い。また、目付が15ｇ／ｍ2より小さいと不織布の強度
が小さく、剛性も小さいので加熱成形での加工性が悪
く、皺がはいったりシートが切断されるなどの問題を生
じやすい。目付が100ｇ／ｍ2より大きいと、本発明の積
層構造をとっても濾過ライフなどがあまり向上しない。DESCRIPTION OF THE PREFERRED EMBODIMENTS The nonwoven fabric used in the laminated nonwoven fabric of the present invention has a fiber diameter of 0.1 to 6 μm and a basis weight of 15 to 100 g / m 2.
Nonwoven fabric. If the fiber diameter is smaller than 0.1 μm, the rigidity of the nonwoven fabric is low even if the filling rate is increased by heating the nonwoven fabric, and the filtration pressure tends to cause a shape loss and shorten the filtration life. Fiber diameter is 6
If it is larger than μm, the filtration life cannot be improved. On the other hand, if the basis weight is less than 15 g / m 2 , the strength of the nonwoven fabric is small and the rigidity is small, so that the workability in the heat molding is poor, and problems such as wrinkling and cutting of the sheet are likely to occur. If the basis weight is more than 100 g / m 2 , the filtration life and the like are not significantly improved even if the laminated structure of the present invention is adopted.
【０００８】本発明に用いられる不織布の素材は特に規
定されないが、ポリオレフィンやポリエステルが加工性
や、型くずれに対する形態安定性が高く好ましい。ポリ
オレフィンとしてはポリエチレンやポリプロピレンが一
般的であり、ポリエステルでは、ポリエチレンテレフタ
レート、ポリトリメチレンテレフタレートポリブチレン
テレフタレートなどがあげられる。[0008] The material of the nonwoven fabric used in the present invention is not particularly limited, but polyolefin or polyester is preferred because of its high workability and form stability against shape collapse. Polyolefins are generally polyethylene and polypropylene, and polyesters include polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate.
【０００９】本発明では不織布が２層以上積層されてい
ることが必要であり、好ましくは３〜５層積層する事が
好ましい。積層される不織布は以下の構成をとることが
必要である。すなわち、上層（上流）側の不織布の（体
積）充填率が0.3〜0.8であることが重要である。上層
（上流）側の不織布は、紡糸条件の選定を行うことや熱
成形などの手段をとることにより充填率を0.3〜0.8に調
整する。充填率をこの範囲にすることで、不織布のフィ
ルム化をできるだけ起こさない範囲で濾過精度を高め、
サブミクロン粒子などを効率よく濾過することが可能に
なる。充填率が0.3未満では３μｍ以下の微小粒子を高
い濾過精度で取ることが難しく、充填率が0.8より大き
いと、繊維が潰れすぎてフィルム化する問題が生じる。In the present invention, it is necessary that two or more nonwoven fabrics are laminated, and preferably three to five nonwoven fabrics are laminated. The nonwoven fabric to be laminated must have the following configuration. That is, it is important that the (volume) filling rate of the nonwoven fabric on the upper layer (upstream) side is 0.3 to 0.8. The filling rate of the nonwoven fabric on the upper layer (upstream) side is adjusted to 0.3 to 0.8 by selecting a spinning condition or taking a means such as thermoforming. By setting the filling rate in this range, the filtration accuracy is increased within a range that does not cause the nonwoven film to be formed as much as possible,
Submicron particles and the like can be efficiently filtered. If the filling factor is less than 0.3, it is difficult to obtain fine particles having a size of 3 μm or less with high filtration accuracy.
【００１０】このように充填率を高くした不織布をその
ままでフィルターとして用いると、表面がかなり平滑で
あるため、通常サボート部材として用いられる多孔プラ
スチック成形体や太い繊維の不織布に濾材が濾過圧によ
ってめり込み、その接触面がサポート材面で蓋をされる
形になってしまうため、濾過に使用されない箇所が増加
して濾過ライフを長くすることが困難になる。たとえ
ば、着色粒子濾過後のフィルターを観察すると、粒子捕
集部は粒子に覆われて表面の色が粒子の色に見えるが、
部分的にフィルターの表面が白っぽく残り濾過に利用さ
れない部分が分散し、この部分が濾過に利用されないこ
とになる。本発明で規定するように下流側に充填率が0.
01〜0.25の不織布を設置すると、驚くべき事に濾過ライ
フは約２倍以上に改善される。[0010] If the nonwoven fabric having such a high filling rate is used as it is as a filter, the surface thereof is considerably smooth. Therefore, the filter medium is immersed into the nonwoven fabric of a porous plastic or a thick fiber which is usually used as a support member by a filtration pressure. Since the contact surface is covered with the support material, the number of portions not used for filtration increases, and it becomes difficult to extend the filtration life. For example, when observing the filter after colored particle filtration, the particle collecting part is covered with particles and the surface color looks like the color of the particles,
Part of the surface of the filter that is whitish and is not used for filtration is dispersed, and this part is not used for filtration. The filling rate on the downstream side as defined in the present invention is 0.
Surprisingly, the filtration life is more than doubled when a nonwoven fabric of 01-0.25 is installed.
【００１１】この範囲の充填率の不織布は表面に適度な
凹凸があり、サポート材との接触面で微小な空間を保持
して開口部が蓋されるのを防止するのに役立っていると
推定される。着色粒子濾過後のフィルターは全面に渡り
粒子に覆われ白く残った部分はほとんどなく、フィルタ
ー面全面が利用される。また、下流側の不織布は、フィ
ルター全体の変形を緩和するクッション材として作用し
ていると推定される。It is presumed that the nonwoven fabric having a filling rate in this range has moderate irregularities on the surface, and is useful for holding a small space at the contact surface with the support material and preventing the opening from being covered. Is done. The filter after the colored particle filtration is covered with particles over the entire surface, and there is almost no portion left white, and the entire filter surface is used. Further, it is presumed that the nonwoven fabric on the downstream side functions as a cushioning material for alleviating deformation of the entire filter.
【００１２】充填率が0.01未満の不織布を下流側に設置
すると、極細繊維不織布の場合は毛羽立ちやすくハンド
リングに問題があり、また、強力も弱く加工工程の通過
性が著しく低下する。充填率が0.25より大きいと、濾過
に供されない部分が増えて濾過ライフが短くなる。If a non-woven fabric having a filling factor of less than 0.01 is placed on the downstream side, the ultra-fine fiber non-woven fabric tends to fluff and has a problem in handling. When the filling rate is larger than 0.25, the portion not subjected to filtration increases, and the filtration life is shortened.
【００１３】本発明では不織布を３層以上積層しても同
様の効果が認められ、規定された充填率の上層側の不織
布と下層側の不織布が必ずしも隣接しなくてもよいが、
隣接していることが特に好ましい。また、間に不織布を
挟む場合は、２枚の不織布の充填率の中間の充填率を持
つことが好ましい。In the present invention, the same effect is recognized even when three or more nonwoven fabrics are laminated, and the upper nonwoven fabric and the lower nonwoven fabric do not necessarily have to be adjacent to each other at a specified filling rate.
Adjacent is particularly preferred. When a nonwoven fabric is sandwiched between the two nonwoven fabrics, it is preferable that the two nonwoven fabrics have a middle filling ratio.
【００１４】積層される不織布の繊維径は、本発明要件
を満たしていれば良いが、同じ平均繊維径あるいは、下
層側をより細い繊維径にすることが好ましい。The fiber diameter of the nonwoven fabric to be laminated may satisfy the requirements of the present invention, but it is preferable that the average fiber diameter is the same or the fiber diameter of the lower layer is smaller.
【００１５】本発明において、不織布の充填率は上層側
の方が高く、上層側と下層側の充填率の比が3〜10であ
ることが好ましく、特に好ましくは4〜６である。この
理由は明らかではないが、充填率の比が３〜１０の範囲
をはずれると、下層側に規定の充填率の不織布を置くこ
とによる改善効果が小さくなる。In the present invention, the filling rate of the nonwoven fabric is higher on the upper layer side, and the ratio of the filling rate on the upper layer side to that on the lower layer side is preferably 3 to 10, particularly preferably 4 to 6. Although the reason is not clear, if the filling ratio is out of the range of 3 to 10, the improvement effect by placing the nonwoven fabric having the specified filling ratio on the lower layer side is reduced.
【００１６】また、上層側の不織布の平均孔径が0.2〜
5.0μｍであり、下層側の不織布の平均孔径が0.5〜30μ
ｍである場合が濾過ライフ改善の点でより効果的であ
る。The average pore size of the upper nonwoven fabric is 0.2 to 0.2.
5.0μm, the average pore size of the lower nonwoven fabric is 0.5-30μ
m is more effective in improving the filtration life.
【００１７】積層される不織布の少なくとも１層にフィ
ブリル状繊維を５〜３０重量％含有されている事が好ま
しい。フィブリル状繊維は、幹の部分の繊維が太く、濾
過操作時の濾過圧による圧縮によりシートがへたって充
填率が高くなりすぎたり、型くずれするのを防止するの
に効果がある。フィブリル状繊維は、熱可塑性であると
熱融着処理により更に形態保持性を改善することが可能
であり好ましい。Preferably, at least one layer of the laminated nonwoven fabric contains 5 to 30% by weight of fibril-like fibers. The fibril-like fibers are thick in the trunk portion, and are effective in preventing the sheet from becoming excessively high due to compression by the filtration pressure at the time of the filtration operation, and preventing the packing ratio from becoming too high and the shape from being lost. The fibril-like fibers are preferably thermoplastic because it is possible to further improve the shape retention by heat fusion.
【００１８】フィブリル状繊維の例として、例えば繊維
長0.5〜3.0mm程度のフィブリル化繊維であるポリオレフ
ィンの合成パルプで、融点が１１０℃以下のものを用い
ると、熱処理などで繊維相互の接着ができるため、不織
布に熱的なダメージが与えても熱収縮の問題を起こすこ
とがないので特に好ましい。フィブリル化繊維長は80mm
以下であることが好ましく、抄紙法を用いるときは、20
mm以下であることが特に好ましい。As an example of the fibril-like fiber, for example, when a synthetic pulp of polyolefin, which is a fibrillated fiber having a fiber length of about 0.5 to 3.0 mm and having a melting point of 110 ° C. or less, can be bonded to each other by heat treatment or the like. Therefore, even if the non-woven fabric is thermally damaged, the problem of heat shrinkage does not occur, so that the non-woven fabric is particularly preferable. Fibrillated fiber length is 80mm
It is preferably the following, when using the papermaking method, 20
It is particularly preferred that it is not more than mm.
【００１９】本発明の積層不織布の好ましい実施形態と
しては、不織布が２ないし５層隣接して積層され、この
積層される各不織布の目付変動率が１０％以下であるメ
ルトブロー法により得られたものであって、隣接する不
織布の上流側の不織布の充填率が0.4〜0.6であり、下流
側の不織布の充填率が0.01〜0.25である積層部を少なく
とも１カ所以上有することが特に好ましい。As a preferred embodiment of the laminated nonwoven fabric of the present invention, two to five nonwoven fabrics are laminated adjacent to each other, and each of the laminated nonwoven fabrics is obtained by a melt blow method in which the basis weight variation is 10% or less. In particular, it is particularly preferable to have at least one laminated portion in which the filling rate of the nonwoven fabric on the upstream side of the adjacent nonwoven fabric is 0.4 to 0.6 and the filling rate of the nonwoven fabric on the downstream side is 0.01 to 0.25.
【００２０】メルトブロー法により得られる不織布は繊
維がランダムに配列されているため濾過精度（効率）を
高くすることが可能である。その際、充填率が0.4〜0.6
であると濾過精度とライフのバランスがよくなり、さら
に形態安定性が良くなる。下層の不織布の充填率が、0.
01〜0.25であることが濾過ライフ改善の点で効果的であ
る。Since the fibers of the nonwoven fabric obtained by the melt blow method are randomly arranged, the filtration accuracy (efficiency) can be increased. At that time, the filling rate is 0.4-0.6
In this case, the balance between the filtration accuracy and the life is improved, and the form stability is further improved. The filling rate of the lower nonwoven fabric is 0.
It is effective that the ratio is from 01 to 0.25 in terms of improving the filtration life.
【００２１】本発明の積層不織布をフィルターとして用
いる際は、粘度が2〜1000ｃｐ（センチポイズ）の液体
を濾過速度0.1〜50ｃｍ／分の濾過速度で濾過に適用す
るのが特に好適である。液体の粘度が高くなると濾過圧
による型くずれの問題や圧縮による濾材の変形が大きく
なりやすいので、下層側に充填率の小さい不織布を設置
すると平面の凹凸による閉塞防止効果やクッション効果
が大きくなる。また、濾過流体はガスや水などの低粘度
の流体でも本発明の効果はあるが、粘度が高い液体ほど
本発明の構成の積層不織布を用いたフィルターは濾過ラ
イフの改善効果が顕著である。When the laminated nonwoven fabric of the present invention is used as a filter, it is particularly preferable to apply a liquid having a viscosity of 2 to 1000 cp (centipoise) at a filtration rate of 0.1 to 50 cm / min. If the viscosity of the liquid is high, the problem of mold collapse due to filtration pressure and the deformation of the filter medium due to compression are likely to increase. Therefore, if a nonwoven fabric with a small filling rate is provided on the lower layer side, the effect of preventing blockage due to unevenness of the plane and the cushioning effect will increase. In addition, although the filter fluid has a low viscosity fluid such as gas or water, the effect of the present invention can be obtained. However, as the viscosity of the liquid increases, the filter using the laminated nonwoven fabric of the present invention has a remarkable effect of improving the filter life.
【００２２】本発明の積層不織布をフィルターとして用
いる際には、積層された不織布の厚みは５0〜300μｍで
あることが望ましい。厚みが5０μｍより小さいとフィ
ルター性能が低下する傾向がある。また、不織布強度も
小さくなって好ましくない。逆に300μｍより大きくし
てもフィルター性能はあまり向上されない。また、積層
された不織布の目付は30〜2００ｇ／ｍ2であることが望
ましく、特に20〜100ｇ／ｍ2が好ましい。When the laminated nonwoven fabric of the present invention is used as a filter, the thickness of the laminated nonwoven fabric is desirably 50 to 300 μm. If the thickness is less than 50 μm, the filter performance tends to decrease. In addition, the strength of the nonwoven fabric is undesirably reduced. Conversely, even if it is larger than 300 μm, the filter performance is not so much improved. Also, the basis weight of the laminated nonwoven fabric is preferably a 30 to 200 g / m 2, especially 20 to 100 g / m 2 is preferred.
【００２３】さらに、本発明の積層不織布の引張強力は
１．５〜３０ｋｇ／５ｃｍ巾であることが好ましい。
１．５ｋｇ／５ｃｍ巾ｇより小さいと強度向上のための
カレンダー加工工程などで不織布切断が生じやすくな
る。Further, the tensile strength of the laminated nonwoven fabric of the present invention is preferably 1.5 to 30 kg / 5 cm wide.
If it is smaller than 1.5 kg / 5 cm width g, the nonwoven fabric is likely to be cut in a calendering step or the like for improving the strength.
【００２４】本発明の積層不織布は、カレンダー加工な
どの熱融着手段により繊維間の接着を強化して、不織布
の強度をより高くなるように改善することが好ましい。
また、別の不織布と積層などにより複合化することも好
ましい。また、引っ張り強度が７ｋｇ／５ｃｍ以上のス
パンボンド不織布やネット状のフィルムと積層すること
も好ましい。The laminated nonwoven fabric of the present invention is preferably improved so that the strength of the nonwoven fabric is increased by strengthening the adhesion between the fibers by means of heat fusion such as calendering.
It is also preferable to composite with another nonwoven fabric by lamination or the like. It is also preferable to laminate with a spunbond nonwoven fabric or a net-like film having a tensile strength of 7 kg / 5 cm or more.
【００２５】[0025]
【実施例】以下に、本発明の積層不織布の実施例を記載
するが、本発明はこれらの実施例に限定されるものでは
ない。本発明で用いた測定方法を以下に示す。 イ．目付（ｇ／ｍ2） 不織布の長手方向を縦方向として、縦20ｃｍ横５ｃｍの
矩形シートの全幅で切り出して、精密天秤で秤量し、測
定値を算術平均して、１ｍ2あたりに換算して目付とし
た。また、目付の標準偏差を平均値で除して目付変動率
（％）を得た。EXAMPLES Examples of the laminated nonwoven fabric of the present invention will be described below, but the present invention is not limited to these examples. The measurement method used in the present invention is described below. I. Weight (g / m 2 ) With the longitudinal direction of the nonwoven fabric as the longitudinal direction, cut out the entire width of a rectangular sheet of 20 cm long and 5 cm wide, weighed with a precision balance, arithmetically averaged the measured values, and converted it per 1 m 2 The basis was used. In addition, the standard deviation of the basis weight was divided by the average value to obtain the basis weight variation rate (%).
【００２６】ロ．厚み（μｍ）および充填率 各不織布シートの中央部で２０ｇ／ｃｍ2荷重下での厚
みを５点測定し、算術平均を不織布の厚みとした。目付
を厚みと不織布素材自身の密度で除して体積充填率を求
めた。B. Thickness (μm) and Filling Rate Five points of thickness under a load of 20 g / cm 2 were measured at the center of each nonwoven fabric sheet, and the arithmetic average was taken as the thickness of the nonwoven fabric. The basis weight was divided by the thickness and the density of the nonwoven fabric material itself to obtain a volume filling ratio.
【００２７】ハ．平均孔径（μｍ） コールター社のポロメータIIにより測定した。試験液は
同社のプロフィル液を使用した。C. Average pore size (μm) It was measured by Coulter porometer II. The test solution used was the company's profile solution.
【００２８】ニ．濾過精度（％） 不織布を直径４７ｍｍφの多孔金属板をサポート材とす
るフォルダーにセットして、粒径0.6μｍのアルミナ粒
子を50ｐｐｍ分散させた粘度5ｃｐの水飴（マルトー
ス）の水溶液を用いて濾過試験を行った。入口濃度と試
験開始2分後の出口濃度を測定して初期の捕集効率を測
定した。圧力が2ｋｇｆ／ｃｍ2になるまでの時間を濾過
ライフとした。 濾過精度（％）＝［1-（出口濃度／入口濃度）］×１０
０D. Filtration accuracy (%) A nonwoven fabric is set in a folder using a porous metal plate having a diameter of 47 mmφ as a support material, and a filtration test is performed using an aqueous solution of maltose having a viscosity of 5 cp in which alumina particles having a particle diameter of 0.6 μm are dispersed at 50 ppm. Was done. The initial concentration was measured by measuring the inlet concentration and the outlet concentration 2 minutes after the start of the test. The time until the pressure reached 2 kgf / cm 2 was defined as the filtration life. Filtration accuracy (%) = [1- (outlet concentration / inlet concentration)] × 10
0
【００２９】（比較例１）平均繊維径1.5μｍ、目付30
ｇ／ｍ2のポリプロピレン製メルトブローン不織布（ポ
リプロピレン樹脂比重0.9g/cm3）を２枚積層して１１０
℃でカレンダー処理して繊維を融着させ、充填率0.51の
積層不織布を得た。フィルター性能を評価したところ、
濾過精度は72％であったが、ライフが2分17秒と短かっ
た。濾過後の積層不織布の表面は白色で粒子の捕集に役
立っていないところが多数認められた。(Comparative Example 1) Average fiber diameter 1.5 μm, basis weight 30
g / m 2 polypropylene melt blown nonwoven fabric (polypropylene resin specific gravity 0.9 g / cm 3 )
The fibers were fused by a calendering treatment at a temperature of ° C to obtain a laminated nonwoven fabric having a filling factor of 0.51. When evaluating the filter performance,
The filtration accuracy was 72%, but the life was as short as 2 minutes and 17 seconds. The surface of the laminated nonwoven fabric after filtration was white, and many places not contributing to the collection of particles were observed.
【００３０】（比較例２）比較例１で用いたポリプロピ
レン製メルトブローン積層不織布に繊維径15μｍ、目付
30ｇ／ｍ2、充填率0.15のポリプロピレン製のスパンボ
ンド不織布を積層して、フィルター性能を評価した。濾
過精度は70％と比較例１と差がなく、濾過ライフも2分2
0秒と短かった。濾過後の不織布の表面も、比較例１と
同様であり、白色で粒子の捕集に役立っていないところ
が多数認められた。Comparative Example 2 The polypropylene melt-blown nonwoven fabric used in Comparative Example 1 had a fiber diameter of 15 μm and a basis weight.
A spunbonded nonwoven fabric made of polypropylene having a filling rate of 30 g / m 2 and a filling rate of 0.15 was laminated, and the filter performance was evaluated. Filtration accuracy is 70%, no difference from Comparative Example 1, and filtration life is 2 minutes 2
It was as short as 0 seconds. The surface of the nonwoven fabric after filtration was also the same as that of Comparative Example 1, and many places were white and did not contribute to the collection of particles.
【００３１】（実施例１）比較例１で用いた充填率が0.
51のポリプロピレン製メルトブローン積層不織布に繊維
径1.5μｍ、目付30ｇ／ｍ2、充填率0.10のポリプロピレ
ン製のメルトブローン不織布を積層して、フィルター性
能を評価した。濾過精度は87％と比較例１より向上した
うえに、濾過ライフも6分46秒と長くなった。濾過後の
積層不織布の表面は、ほぼ全面がアルミナ粒子で覆われ
ており、白色で粒子の捕集に役立っていないところはほ
とんど数認められた。(Example 1) The filling rate used in Comparative Example 1 was 0.
A melt blown nonwoven fabric made of polypropylene having a fiber diameter of 1.5 μm, a basis weight of 30 g / m 2 , and a filling rate of 0.10 was laminated on 51 melt blown laminated nonwoven fabrics made of polypropylene, and the filter performance was evaluated. The filtration accuracy was 87%, which is higher than that of Comparative Example 1, and the filtration life was also longer at 6 minutes and 46 seconds. Almost the entire surface of the laminated nonwoven fabric after the filtration was covered with alumina particles, and almost all of them were white and did not contribute to the collection of particles.
【００３２】（実施例2）平均繊維径1.5μｍ、目付30ｇ
／ｍ2のポリプロピレン製メルトブローン不織布（ポリ
プロピレン比重0.9g/cm3）を単層で１１０℃でカレンダ
ー処理して繊維を融着させ充填率0.50の不織布を得た。
この不織布を２枚積層して、その下に実施例１で使用し
た繊維径1.5μｍ、目付30ｇ／ｍ2、充填率0.10のポリプ
ロピレン製のメルトブローン不織布を積層して、フィル
ター性能を評価した。液体フィルターの性能を測定した
ところ、濾過精度が91％と高く濾過ライフも7分5７秒と
長かった。フィルター上面の外観も実施例１と同様に均
一でデッド部はあまり認められなかった。Example 2 Average fiber diameter: 1.5 μm, basis weight: 30 g
/ M 2 of polypropylene meltblown nonwoven fabric (polypropylene specific gravity 0.9 g / cm 3 ) was calendered at 110 ° C. in a single layer to fuse the fibers to obtain a nonwoven fabric having a filling factor of 0.50.
Two nonwoven fabrics were laminated, and a polypropylene meltblown nonwoven fabric having a fiber diameter of 1.5 μm, a basis weight of 30 g / m 2 , and a filling rate of 0.10 used in Example 1 was laminated thereon, and the filter performance was evaluated. When the performance of the liquid filter was measured, the filtration accuracy was as high as 91%, and the filtration life was as long as 7 minutes and 57 seconds. The appearance of the upper surface of the filter was uniform as in Example 1, and few dead portions were observed.
【００３３】（実施例３）比較例１と同じ平均繊維径1.
5μｍのポリプロピレン製メルトブローン不織布（ポリ
プロピレン比重0.9g/cm3）を製造する際に反毛機により
２ｄの捲縮ポリエステル繊維（東洋紡績株式会社製ＭＳ
７）を開繊して吹き込むことにより目付40ｇ／ｍ2複合
不織布を得た（短繊維分の重量分10ｇ／ｍ2相当）。こ
の不織布を２枚積層して１１０℃でカレンダー処理して
充填率0.50の不織布を得た。この不織布を２枚積層し
て、その下にさらに繊維径1.5μｍ、目付30ｇ／ｍ2、充
填率0.10のポリプロピレン製のメルトブローン不織布を
積層して、フィルター性能を評価した。液体フィルター
の性能を測定したところ、濾過精度が90％と高く濾過ラ
イフも8分13秒と長かった。フィルター上面の外観も実
施例１と同様に均一でデッド部はほとんど認められなか
った。(Example 3) Same average fiber diameter as Comparative Example 1 1.
When producing a melt-blown nonwoven fabric made of polypropylene of 5 μm (specific gravity of polypropylene: 0.9 g / cm 3 ), 2d crimped polyester fiber (MS manufactured by Toyobo Co., Ltd.)
7) was obtained basis weight 40 g / m @ 2 composite nonwoven fabric by blowing by spreading a (weight fraction 10 g / m 2 corresponds short fiber content). Two nonwoven fabrics were laminated and calendered at 110 ° C. to obtain a nonwoven fabric having a filling factor of 0.50. Two nonwoven fabrics were laminated, and a polypropylene meltblown nonwoven fabric having a fiber diameter of 1.5 μm, a basis weight of 30 g / m 2 , and a filling rate of 0.10. When the performance of the liquid filter was measured, the filtration accuracy was as high as 90%, and the filtration life was as long as 8 minutes and 13 seconds. The appearance of the upper surface of the filter was uniform as in Example 1, and almost no dead portion was observed.
【００３４】[0034]
【発明の効果】本発明によると、寸法安定性や形態保持
性に優れ、濾過精度と濾過ライフとのバランスに優れた
気液フィルターに好適な積層不織布を提供することがで
きる。また、高粘度の液を用いても濾過精度や濾過ライ
フに優れる濾過方法が提供可能である。According to the present invention, it is possible to provide a laminated nonwoven fabric which is excellent in dimensional stability and shape retention, and which is suitable for a gas-liquid filter having an excellent balance between filtration accuracy and filtration life. Further, a filtration method which is excellent in filtration accuracy and filtration life even when a liquid having a high viscosity is used can be provided.
Claims (6)
／ｍ2である不織布が少なくとも２層以上積層されてお
り、上層側の不織布の充填率が0.3〜0.8であり、下層側
の不織布の充填率が0.01〜0.25であることを特徴とする
フィルター用積層不織布。1. The fiber diameter is 0.1 to 6 μm and the basis weight is 15 to 100 g.
/ M 2 , wherein at least two or more nonwoven fabrics are laminated, the filling rate of the upper nonwoven fabric is 0.3 to 0.8, and the filling rate of the lower nonwoven fabric is 0.01 to 0.25. Laminated non-woven fabric.
3〜10であることを特徴とする請求項１に記載のフィル
ター用積層不織布。2. The filling ratio of the nonwoven fabric on the upper layer side and that on the lower layer side is
The laminated nonwoven fabric for a filter according to claim 1, wherein the number is 3 to 10.
ｍの間にあり、下層側の不織布の平均孔径が0.5〜30μ
ｍであることを特徴とする請求項１〜２記載のフィルタ
ー用積層不織布。3. The nonwoven fabric on the upper layer side has an average pore size of 0.2 to 5.0 μm.
m, the average pore size of the lower nonwoven fabric is 0.5 to 30μ
3. The laminated nonwoven fabric for a filter according to claim 1, wherein m is m.
ィブリル状繊維を５〜３０重量％含有する請求項1〜３
に記載のフィルター用積層不織布。4. The laminated nonwoven fabric according to claim 1, wherein at least one layer of the nonwoven fabric contains 5 to 30% by weight of fibril-like fibers.
5. The laminated nonwoven fabric for a filter according to 4.
率が１０％以下であるメルトブロー法により得られた不
織布であって、隣接する不織布の上層側の不織布の充填
率が0.4〜0.6であり、下層側の不織布の充填率が0.01〜
0.25である積層部を少なくとも１カ所以上有することを
特徴とする請求項１〜４に記載のフィルター用積層不織
布。5. The nonwoven fabric laminated adjacently is a nonwoven fabric obtained by a melt blow method having a basis weight variation of 10% or less, and the nonwoven fabric on the upper layer side of the adjacent nonwoven fabric has a filling rate of 0.4 to 0.6. Yes, the filling rate of the lower nonwoven fabric is 0.01 to
The laminated nonwoven fabric for a filter according to any one of claims 1 to 4, wherein the laminated nonwoven fabric has at least one laminated portion having a thickness of 0.25.
布をフィルターに用いて、粘度が2〜1000センチポイズ
の液体を濾過速度0.1〜50ｃｍ／分の濾過速度で濾過す
る方法。6. A method of filtering a liquid having a viscosity of 2 to 1000 centipoise at a filtration rate of 0.1 to 50 cm / min using the laminated nonwoven fabric according to claim 1 as a filter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2163699A JP2000218113A (en) | 1999-01-29 | 1999-01-29 | Laminated nonwoven fabric for filter and filtration method using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2163699A JP2000218113A (en) | 1999-01-29 | 1999-01-29 | Laminated nonwoven fabric for filter and filtration method using the same |
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| Publication Number | Publication Date |
|---|---|
| JP2000218113A true JP2000218113A (en) | 2000-08-08 |
Family
ID=12060570
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2163699A Pending JP2000218113A (en) | 1999-01-29 | 1999-01-29 | Laminated nonwoven fabric for filter and filtration method using the same |
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| Country | Link |
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Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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